The Catalans' hopes of another Wembley win hang in the balance following their dreadful display at San Siro in the last 16 of the Champions League

ANALYSISBy Ben Hayward | Spanish Football Writer

This was Barcelona, but not as we knew it. The game's greatest group of players from the last five years produced a performance lacking in heart, soul, fight and ideas as they fell 2-0 to an average AC Milan side at San Siro on Wednesday, leaving Lombardy with their Champions League hopes in the balance. Afterwards, some of their stars attempted to explain the damaging defeat but were lost for words at the nature of their disappointing display. Perhaps Andres Iniesta came closest when he said simply: "We didn't show up."

That was an understatement.

Barcelona may feel aggrieved by the first goal, in which Cristian Zapata's raised hands helped set up Kevin-Prince Boateng to shoot past Victor Valdes, yet the Catalans could have few complaints about the overall outcome. They had deserved little more.

When these two teams met in the group stages of the Champions League at the same stadium last season, Pep Guardiola opted for an adventurous 3-4-3 formation which left his side somewhat exposed at the back but ensured an extra man in midfield. It made for an enthralling encounter which Barca won 3-2.

Then, when Barca travelled to Milan in the last eight of the competition in March, Guardiola reverted to a more conservative 4-3-3. That formation, however, became a 3-4-3 when Barca were in possession, as Dani Alves pushed forward to slot into the midfield and ensure an extra man when the Catalans had the ball. Barca were the better team that day, but Milan turned in a disciplined defensive display to hold out for a goalless draw (which was ultimately insufficient as they lost the second leg 3-1 at Camp Nou).

Try as he might, the Argentine could not weave his usual magic with the ball, as he was swarmed by red and black shirts whenever he got on the ball in the opposition half.

Stripped of the services of Zlatan Ibrahimovic and Thiago Silva in the summer as well as many more, this Milan team is noticeably weaker than last season's side. Yet as this match got underway, the Italians seemed to stifle Barcelona with relative ease, squeezing the spaces with two tight lines in defence and midfield.

Barca had 66 per cent of the possession but the Catalans were unable to make it count: Alves was unable to get forward like last year as he was pushed back by Milan's midfield; Xavi was slow to recycle possession and well short of his best; Cesc Fabregas failed to find his range or his bearings; Iniesta looked less happy further forward on the left; Lionel Messi dropped deep and found no joy wherever he went.

Although they had the ball for two thirds of the playing time, Barca's territorial advantage was scarce and they managed just two attempts on target, fewer than in any game this season and their worst return since the Champions League semi-final second leg at Chelsea in 2009.

That game finished happily for Barca as Iniesta hammered home a dramatic late leveller. This one, however, did not. There appeared little or no urgency to their play until Sulley Muntari made it 2-0 with 10 minutes remaining. By then, though, it was too late. One of the features of this great Barca side is how they react in big matches when they go behind. On Wednesday, there was no reaction whatsoever.

Not even their pressing was in evidence. Once, in the first half, Pedro raced back to win a ball which had been lost further upfield. It was a reminder of just how good Barcelona are at winning back possession when they have lost it, doubling up on their opponents to regain the ball, believing it to be theirs.

But there was no such belief on Wednesday and, aside from that one isolated incident, the fight was missing. Indeed, not one Barca player comes out of this match with much credit.

Certainly not Messi. The Argentine found himself in a physical battle with Milan's defenders and dropped deep to find space but was tracked by men in red and black wherever he went and his influence on the game was curtailed completely. The 25-year-old managed just two shots in the 90 minutes and one of those was a wild free kick which sailed well over the bar. It was his poorest performance in a long, long time.

Despite their apparent lack of motivation, Barca seemed content while the score remained goalless, perhaps looking ahead to a comfortable clash at Camp Nou. But before this match, the Catalans had conceded in their previous nine games and their defensive difficulties cost them dearly.

Earlier on this season, with both Puyol and Gerard Pique out, Barca's defensive troubles were understandable. Now, however, both are back and the team is still leaking goals. Puyol, although committed as ever, was dragged out of position several times, including the second goal, and will have wanted to do better against the side he so admires. He remains Barca's natural leader, yet he was unable to lead by example here.

So there is much to address ahead of the second leg for Barca's interim coach Jordi Roura, who endured an unhappy return to a ground which will have brought back bad memories, as it was at San Siro in 1989 that he suffered an injury in the Uefa Super Cup against Milan which would end his career as an elite footballer. And on Wednesday's showing at the same stadium, his coaching career at the highest level may not last too much longer, either.